A massive late winter snow storm roared out of the Southeast and into the Northeast overnight, idling hundreds of flights and promising to make Monday's commute treacherous as motorists contend with what could end up with more than a foot of snow in spots.

More than a million households remain without power after snow and ice slammed the country from Texas to Maine, disrupting hundreds of flights and forcing Kentucky state troopers to use four-wheelers to find stranded residents.

A wave of fare sales has spread across the airline industry in the early days of the new year as the weak economy continues to put pressure on carriers to fill seats even after they drastically reduced capacity and some expressed willingness to cut more.

As airline passengers grow wary, and perhaps weary, of the more fees and higher ticket prices, some U.S. carriers may look to onboard advertisements as a way to raise revenue without further tapping customers' wallets and patience.